1. Field of the Invention
This invention relates to the field of showing images on different display devices, and particularly to display devices which have different capabilities for viewing the content.
2. Description of the Related Art
Messages may be transmitted over a wireless communications network to a mobile terminal, such as mobile phone, together with, or independently of an audio signal. The message may contain various types of content to serve various functions, that are already publicly available or are becoming available shortly. The content may consist of still pictures or video. These messages may be automatically sent to a recipient or there may be services which respond to a recipient's request for a specific service.
The display capabilities of currently available mobile terminals are limited because of the size and weight requirements on these compact devices. A mobile terminal display may be provided to view an incoming video signal, but because of the above mentioned facts, users would not enjoy watching multiformatted images or video on such a display. This problem with a small display is especially problematic for visually impaired people.
It is therefore desirable to find a way to view the content received with a mobile terminal on a separate display that has better display capabilities. A television receiver display or a computer monitor are examples of this kind of display having better display capabilities. Being able to display video sent over a mobile terminal on a larger display device, like a television display, would also allow a service provider to provide additional optional services to provide a user with added value, and avoid unnecessarily draining of the mobile terminal's battery by displaying the video on a separate display device that has a separate power source.
Recently, low power RF systems have been proposed for providing communications between a plurality of transceivers through a short range communications link. One such short range RF technology is currently under development and is referred to as “Bluetooth”. This system will be commercially available in the near future and it operates in the open spectrum around 2.45 GHz. This unlicensed radio band, called Industrial, Scientific, Medical (ISM) band is globally available. The operating range of this RF system is approximately 10 meters for a normal power mode and has proven to be economically efficient. It is planned that a Bluetooth chip having these characteristics will be inserted in all kinds of electrical devices for enabling communication between separate devices. In PCT Application No. WO 0018025, such a Bluetooth link between a Bluetooth enabled mobile terminal and a Bluetooth enabled data terminal, such as a PC, is disclosed.
It would be particularly advantageous to enable the user to view the content, such as a video clip on a larger display, while the user is actually holding the mobile terminal, and allow the user to select what is viewed using the mobile terminal, or to otherwise use the mobile device while viewing the video clip. This would be best implemented using a wireless link between the mobile terminal and the external display device. U.S. Pat. No. 5,880,732 presents a method and apparatus enabling one specific type of usage of a remote display device connected to a mobile telephone. However, the invention offers only a partial solution to the problem, because the system allows only the textual message appearing on the telephone display to be viewed on the remote display. The system does not take into consideration the different displaying capabilities of the devices such as that the remote display may be capable of displaying images that the mobile telephone cannot, which makes the system inadequate for effective use.